SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '25c043c4a82f2e9d7528b53536706616f219ce4175b3013a71a135bcda853ef6' 
  AND token = '0NtPVyPmXJVC68tcqvZTMUHkTuD9EgGAmN+jzNOGXxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}